In this paper, we propose an adaptive path planning scheme considering the length
of movement path and number of beacon messages of a mobile beacon for its energy efficiency,
where the sensor nodes are randomly deployed. Contrary to the previous studies
that utilize mobile beacons (nodes sending beacon messages) only on the basis of a random
movement method or predefined static movement paths, the proposed scheme provides
energy-efficient and adaptive movement path construction with low computational
complexity. The movement path also includes beacon positions in which the mobile
beacon broadcasts beacon messages containing the information of its current position.
The random movement methods are not concerned about the energy of the mobile beacon.
In randomly deployed environments, it is not easy to obtain precise field information for
static movement path decisions. Thus, we propose the adaptive path planning scheme
which can operate without this information in randomly deployed wireless sensor networks,
and improve the energy efficiency of the mobile beacon. The candidate areas that
limit the search space are devised so as to provide low complexity. The performance evaluation
shows that the proposed scheme reduces the movement distance and number of
beacon messages of the mobile beacon by comparison with other methods.

Received August 13, 2009; revised March 8 & July 5 & August 18, 2010; accepted August 31, 2010.
Communicated by Wanjiun Liao.
* The preliminary version has been presented in the IEEE International Conference on Computer Communications
and Networks, August 13-16, 2007, Turtle Bay Resort, Honolulu, Hawaii, USA, and it was supported by
IEEE CommSoc (Technical Co-Sponsorship) and Nokia.